Nibbler



C. DODEGGE Dec. 7, 1954 NIBBLER Filed April 50, 1952 ATTORNEYS United States Patent This invention relates to shearing attachments for portable power unitsand, more particularly, to mb'olers 'for attachment to portable power units such as electric drills, and the like.

Nibblers of the general character to which my invention relates have been heretofore known in the art. However, the nibblers previously known have had certain inherent disadvantagesV such as, for example, being of -relatively complicated construction; and. embodying' constructions wherein the` punch of the nibbler was not efficiently supported, and theV like.

The primary object of my invention is to aft'ord a novel nibbler wherein the punch thereof is firmly and positively held against undesired movement in a novel and expeditious manner.

Another object is to 'so construct a novel nibbler that thev punch is supported in bearings at both ends in a novel' and. expeditious manner.

A` further object of my invention is to aiford such a nibbler. wherein a shear plate or cutter blade may be embodied, in a novel manner, as an. integral. partV of one of the aforementioned bearings, which may be' quickly and easily inserted in, and withdrawn from, the housing` of thenibbler.

Yet another object of my invention is to afford a nibbler' embodying novel and efficient bearings of the aforementioned character, wherein the. bearings and the openings therein are constructed in a novel and expeditious manner, whereby the: commercial.. production of the bearing is facilitated, and the assembly of the bearing in the nibbler unit may be quickly and easly eifected'.

A further object is toafford a` nibbler which is relatively small in Size, but which aifords` an effective attachment for electric hand drills and the like, and which is eificient in. operation and may be readily and economically produced commercially.

Other and further objects of the present invention will be apparent from the following description and cl-aims and are. illustrated in the accompanying drawing which, by way of illustration,` Shows a preferred em'bodiment of the present invention and the principle thereof and what I. now consider to be' the. best mode inwhich I. have contemplated applying. that principle. Other embodiments of the invention embodying the same or equivalent principle may be: used.v and. thef structural changes may be made as. desired by those skilled theA art without de- .parting from the present inventionand the purview of the appended claims.

In the drawings:

Fig. 1 is a side elevational` view of a nibbler embodying the principles: of my invention Figi 2 is va longitndinal, sectional view, taken. substant'ially along the line 2-2 in Fig. 1.

Fig. 3 is a longitudinal, sectional view taken substantially along the line 3-3 in Fig. 2;

Fg. 4 is a sectional view taken substantially along the line 4-4 in Fig. 3; and

Fig. 5 is a detail Sectional view taken substantially along the line 5-5 in Fig. 3.

A nibbler 1"0 is shown in the drawings to illustrate the preferred embodiment` of my invention.

As is best seen in Fig. 3, the nibbler comprises, in general, a housing 12 in which a ram or plunger 14 is reciprocably mounted inbearings 16 and 17, the plunger 14 being connected to a drive unit 19 for reciprocation relative to a shear plate or blade 21, all? of which will be discussed in greater detail presently.

2,6%,44 Patented Dec. 7, 1954 The housing 12 is preferably a one-piece casting having two interconnecting chambers 23 and 24, Fig. 3, therein. The chamber 23' affords the opening in which the ram 14 is mounted, and the chamber 24V aifords the opening in which the drive unit 19 is mounted for connection to the ram 14, as will be discussed in greater detail presently.

The chamber 23v extends longitudinally of the housing 12 from the front wall 25 and terminates in a closed end 26 in spaced relation to the outer surface of the rear wall 27 of the housing 12. Throughout the. major portion of its length, the chamber 23 eomprises a substantially ,cylindrically shaped portion or chamber 29 having a uniform bore. However, the rear end portion of the chamber 23 is of substantially less cross sectional size than the chamber 29, tov thereby afford a rear bearing chamber 30v of considerably reduced cross section.

The bearing 16 comprises-an elongated member having a substantially cylindrical Shape shank 32, on one end of which is mounted an enlarged head 33, and from the other end of which project two diametrically opposed, and substantially parallel ears 32a and 32b, Figs. 2 and 3.

The bearing 16 is mounted in the housing 12 with the shank 32. and the' ears 32a and 32b disposed in snug engagement with the walls of the chamber 29, and with the enlarged head 33 disposed in abutting relation to the front wall 25 of the housing 12.

The bearing 16 is releasably secured in the housing 12 by means of a screw 34 which extends through a portion of the housing 12 into. an opening 37 of substantially the same size and Shape in the bearing 16. The screw 34 is held in proper adjusted position by suitable means such as a lock-nut 40.

The outer Surfaces 35 and- 36 of the ears 32aand 32b, respectively, Fig. 4, are arcuate in Shape,l conforming Sub- Stantially' to the circular Shape of the walls of the chamber 29 to aiford Aa good bearing surface thereagainst. The inner surfaces 38 and 39, respectively, of the ears 32a and 32b are flat and substantially parallel to each other to thereby, together with the adjacent portion of the Walls of the chamber 29, define a slot 45 of quadrangular crosssection and having two opposite sides which are fiat and substantially parallel aiforded by the inner surfaces 38 and 39 of the ears32a and 32b.

Forwardly of the slot 45, an opening 41 extends longitudinally through the bearing 16, Figs. 2 and 3, to receive the ram or plunger 14 as will be discussed in greater detail presently. The opening 41 varies in cross Sectional size and Shape at different portions of its length. Thus, it will be seen that in the front end portion' of the bearing 16, the opening 41 is in the form of an open ended recess 42 of substantially circular cross section. lmmediately behind the recess 42, and inter-connected therewith, the adjacent portion of the opening 41 comprises a passageway 43 of substantially circular shaped cross section, the passageway 43 being of reduced cross section from that of recess 42. The next portion of the opening 41, immediately behind the passageway 43, eomprises a passageway 44 of substantially circular shaped cross section, and the cross section of this passageway 44 is substantially greater than that of either the recess 42 or passageway 43. The passageway 44 is` axially aligned with the slot 45 and the diameter thereof is of the same length as the distance between the inner Surfaces 38 and 39 of the ears 32aand- 32b.

The plunger 14, which is reciprocably mounted in the bearings 16 and 17, embodies an elongated block 47, in one end of which is mounted a punchV 48. Like the opening of 41 in the bearing 16, the block 47 varies in cross sectional Shape and size throughout its length. Thus, it will be Seen that the inner end portion 51 of the block 47 is substantially circular shaped in cross section and fits relatively snugly into the correspondingly circular shaped opening 17a in the bearing 17. Immediately forward of the inner end portion 51 of the block 47, an intermediate portion 53, of substantially square cross section, is disposed. This latter portion of .the block'47 is of Such size that the upper and lower faces 54 and 55 thereof'engage the inner faces 38 and 39,

of the ears 32b and 321: of the bearing 16, Fig. 4.

Another portion 57 of the block 47 is disposed forwardly of the square portion 53 thereof, and is. connected thereto by a connecting portion 58 of reduced cross sectional size. This other portion 57 is circular in cross section, and is of a size corresponding to the cross sectional size of the passageway 44 in the opening 41, to afford a bearing surface which fits relatively snugly in the passageway 44. The forward end portion 59 of the block 47 projects forwardly from the circular portion 57, and is preferably of the circular shape, but is of reduced cross section so that it does not engage the sides of passageway 44.

With this construction of the block 47, it will be seen that this member may be readily constructed of bar stock, the portions 51, 57, 58 and 59 being readily turned on a lathe, or the like, and the portion 45 being readily machined by means of a shaper, a milling machine, or the like. In this latter connection it will be noted that the reduced portion 58 of the block 47 affords sufficient clearance between the square portion 45 and the circular portion 57 to enable proper Shaping of the square portion 45 without striking the portion 57, which, it will be remembered is of the same cross sectional size.

A recess having an internally threaded enlarged portion 61 and a reduced inner portion 62 is formed in front end portion of the end portion 59 of the block 47, Fig. 3, for reception of one end portion of the punch 48 as will be presently explained.

The punch 48 has an inner end portion 65 and a major body portion 67 of the same cross-sectional size separated by an enlarged threaded portion 64 disposed therebetween, Fig. 3. The threads 64 and the inner end portion 65 of the punch 48 are so constituted and arranged that when the threads 64 are screwed into operative position in the threaded recess 61 -in the block 47, the inner end 65 of the punch 48 fits snngly into the recess 62 and abuts the inner end of the recess 62, to thereby firmly and positively support the punch 48 against movement relative to the block 47. This, it will be seen, positively holds the punch 48, and also protects the threads 64 against the stresses encountered in the operation of the punch.

Forwardly of the block 47, the main body portion 67 of the punch 48 is slideably mounted in the passageway 43 of the bearing 16, and fits relatively snugly therein. The forward end portion 68 of the punch 48 is of somewhat smaller cross section than the main body portion 47, and thereby affords a forwardly facing shoulder 69 at the junction of the end portion 68 and the body portion 67, Fig. 3. This shoulder 69 forms the cutting edge of the punch 48, as will be presently explained.

Between the ends of the passageway'43, a substantially inverted U-shaped slot 71 is formed in the enlarged head 33 on the bearing 16. The slot 71 has an upwardly opening top portion 71a, Fig. 3, and two laterally opening legs 71b and 71c, Fig. 2, projecting downwardly from the top portion 71a. The top portion 71a extends transversely across the upper forward portion of the enlarged head 33 immediately above a relatively narrow fiange 73, Figs. 3 and 5, which connects the shear plate 21 to the main body portion of the enlarged head 33, and the outwardly opening legs 71b and 71c, which project downwardly from the top portion 71a, are disposed on opposite sides of the fiange 73, Fig. 2.

As is best seen in Figs. 3 and 5, the flange 73 is Vertically aligned with the passageway 43 and is disposed immediately therebelow with the upper edge of the flange 73 disposed tangentially to the passageway 43. Thus, the top portion`71a of the slot 71 separates the passageway 43 into a forward end portion 43a disposed in the shear plate 21, and a rear end portion disposed in the main body portion of the enlarged head 33, Pig. 3.

The forward end portion 68 of the punch 48, which is of suiciently reduced cross section that it does not engage the side-walls of the passageway 43, is of such length that, when the ram 14 is in fully retracted position as shown in Fig. 3, the end portion 68 is disposed in both the forward end portion 43a and the rear end portion 43h of the passageway 43 with the shoulder 69, between the portions 67 and 68 of the punch 48, disposed in retracted position in the rear end portion 43h of the passageway 43. When the ram 14 is moved into full forwardly disposed position, upon rotation of the drive unit 19, as will be presently explained, the punch 48 is so positioned thereby that the main body portio'n 67 thereof extends into the forward end portion 43a of the passageway 43 sufi'iciently to carry the shoulder 69 forwardly past the shearing edge 21a on the shear plate 21, the shearing edge 21a being that rear edge portion of the shearing plate which defines the rear end of the forward portion 43a of the passageway 43. It is this movement of the shoulder 69 past the shearing edge 21a which effects shearing of work pieces fed into the slot 71 of my novel nibbler during operation of the latter as will be presently discussed.

The drive mechanism 19, by which the plunger 14 is reciprocated in the bearings 16 and 17, comprises a drive shaft 85 journaled in a bearing 86 mounted in the chamber 24. One end portion 87 of the drive shaft 85 projects outwardly from the housing 12 to afford a coupling member by which the drive shaft 85 may be connected to a portable hand type power tool such as, for example, an electric drill, or the like, the coupling member 87, in operation, being engaged in the jaws of the chuck on such a drill.

A roller 89 is eccentrically mounted on the inner end of the drive shaft 85, and is disposed in a slot 91, formed in, and extending transversely across, the lower face of the square portion 53 of the block 47 Figs. 2 and 3. Thus it will be seen that on rotation of the drive shaft 85, the roller 89, through its connection with the block 47, is effective to reciprocate the plunger 14 in the bearings 16 and 17. The roller 89 is so disposed on the drive shaft 85 that upon a complete rotation of the latter, the roller is effective to reciprocate the ram 14 between the aforementioned fully retracted position wherein the punch 48 is disposed in the position shown in Fig. 3, and the aforementioned full forwardly disposed position wherein the shoulder 69 is disposed forwardly of the shearing edge The drive shaft 85 is releasably secured in the housing 12 by a snap-ring 92 mounted in a groove or slot 93 in the outer end portion of the chamber 24 in the housing 12, the snap-ring 92 being engaged with a washer 94 disposed in abutting engagement with an outwardly facing shoulder 85a on the drive shaft 85.

An opening 95 is provided through the top of the housing 12 which communicates with the chamber 41, and aifords means by which suitable lubricants such as, for example, grease, may be inserted in the Chamber 41 to thereby lubricate the plunger 14 and the drive shaft 85. A screw plug 96 is mounted in the opening 95 to aiford a removable cover for the opening.

In the operation of my novel nibbler 10, the coupling member 87 may be mounted in the chuck of a portable hand drill, or the like, and the drive shaft 85 driven thereby. As previously mentioned, the rotation of the drive shaft 85 is effective to reciprocate plunger 14, and therefore to reciprocate the cutting edge 69 on the punch 48 back and forth across the shearing edge 21a on the shear plate 21.

The work to be cut, such as, for example, tin or other suitable sheet metal, may then be fed downwardly into the top portion 71a of the slot 71 into engagement with the side of the punch 48. With the punch 48 being reciprocated by the drive unit 19, the movement of the shoulder 69 thereon past the shearing edge 21a, is effective to cut into the work piece. The shoulder 69 on the punch 48 is relatively narrow, being preferably on the order of fifteen-hundredths of an inch, and therefore, it will be seen that the shearing of the work-piece is accgmplished by a rapid series of relatively small cuts or ites.

The flange 73 is gradually tapered inwardly from the top toward the bottom, as is best seen in Fig. 5, which enables the nibbler 10 to be readily turned during a nibbling operation for following a tortuous cutting line.

In such shearing Operations of my novel device, it will be seen that the ram 14 is positively and efiicently supported against transverse movement at the rear end thereof by the portion 51 disposed in the bearing 17; at the central portion by the portions 53 and 5'7 disposed in the slot portion 45 and the passageway 44, respectively, of the bearing 16; and at the forward end portion by the body portion 67 of the punch 48 disposed in the passageway 43 in the bearing 16.

Also, it will be seen that the ram 14 is also positively and effectively held against rotation in the housing 12 during operation of my novel nibbler 10 by the engagement of the square portion 53 of the block 47 with the ears 32b and 32s, and the positive securing of the bearing 16 by the screw 34 disposed in the housing 12 and the opening 37.

In addition, it will be see'i that the punch 48 is positively and efectively supported in the block 47 of the ram 16 against both lateral and longitudinal movement relative thereto by its combination threaded and abutting engagement therein.

In addition to being effective and efficient in operation, my novel nibbler is so constituted and arranged that it may be readily and economically manufactured commercially and may be quickly and easily assembled and disassembled.

Thus, for example, it will be seen that the housing 12 may be readily constructed as a one-piece casting, and the other parts thereof may be readily constructed of readily available stock, the aforementioned other parts being so constructed that the necessary machining operations thereon may be readily accomplished.

Also, for example, in assembling my novel nibbler, the bearings 17 and 86 may be first inserted into position; the punch 48 may be screwed into the block 47; the ram 14 may then be inserted forwardly into the bearing 16; the bearing 16 and the ram 14 may then be slipped rearwardly into position in the housing 12; the screw 34 and lock nut 40 may then be placed in position; the drive unit 19 may then be inserted into position in the housing 12; and the washer 94 and the snap-ring 93 may then be placed in operative position.

From the foregoing it will be seen that I have atforded a novel nibbler which may be readily constructed, is quickly and easily assembled and disassembled, and which is effective and efiicient in operation.

Hence, while I have illustrated and described the preferred embodiments of my invention, it is to be understood that these are capable of Variation and modification, and I therefore do not wish to be limited to the precise details set forth, but desire to avail myself of such changes and alterations as fall within the purview of the following claims:

I clam:

1. A shearing attachment for a portable hand-type power tool or the like, comprising a housing, two spaced bearings mounted in said housing, an elongated plunger recprocably mounted in said bearings, said plunger having two oppositely disposed end portions with each of said end portions mounted in and supported by a respective one of said bearings, a shear blade mounted on one of said bearings, said plunger including a punch projecting outwardly from said housing toward said blade and being reciprocable relative to said blade upon reciprocation of said plunger in said bearings, and means operatively connected to said plunger for drivingly connecting said plunger to such a power tool for so reciprocating said plunger.

2. A shearing attachment for a portable hand-type power tool or the like, comprising a housing, two bearings mounted in said housing, one of said bearings being removably mounted in said housing and having a shear blade mounted on one end portion thereof outwardly of said housing, a plunger recprocably mounted in said bearings, said plunger including a punch projecting outwardly from said housing toward said blade and reciprocable relative to said blade upon reciprocation of said plunger in said bearings, and means mounted in said housing and connected to said plunger for operatively connecting said plunger to such a power tool for reciprocating said plunger.

3. A shearing attachment for a portable hand-type power tool or the like, comprising a housing, two spaced bearings mounted in said housing, an elongated plunger recprocably mounted in said bearings, said plunger having two oppositely disposed ends with each of said ends mounted in and supported by a respective one of said bearings, a shear blade mounted on one of said bearings, said plunger comprising a block slidably mounted in said bearings, and a punch removably mounted in said block and projecting outwardly from said housing toward said blade, said block having a recess formed therein, and said punch having one end portion threadedly engaged with said block in said recess and having theend extremity of said end portion disposed in abutting relation to a portion of said block, and means operatively connected to said block for drivingly connecting said block to such a power tool for reciprocating said block and said punch relative to said blade.

4. A nibbler for attachment to a portable hand tool and comprising a housing, two bearings mounted in said housing in spaced relation to each other, an elongated plunger recprocably mounted in said bearings and projecting outwardly of said housing for reciprocation into and out of said housing, one end of said plunger being mounted in one of said bearings, said plunger having another end portion of substantially circular cross-section and an intermediate portion of quadrilateral cross-section, said intermediate portion having two flat substantially parallel sides, the other of said bearings having a substantially circular-shaped bearing portion supportingly engaged with said other end portion of said plunger and a slotted portion having two flat substantially parallel sides supportingly engaged with said intermediate portion of said plunger, means mounted on said other bearing and disposed outwardly of said housing and defining a shearing edge, means on said plunger defining a shearing edge, said last mentioned shearing edge being disposed on said plunger in position to reciprocate transversely to, and adjacent to, said first mentioned shearing edge upon said reciprocation of said plunger, and means connected to said plunger for drivingly connecting said plunger to such a hand tool for reciprocation thereby.

5. A nibbler for attachment to a portable hand-type tool such as an electric drill, or the like, comprising a housing, said housing having two elongated, outwardly opening, interconnected chambers disposed transversely to each other, two bearings mounted in one of said chambers in spaced relation to each other, one of said bearings being of elongated construction and being removably mounted in said one chamber and having an end portion projecting outwardly from said housing, said one bearing having an opening extending substantially axially through the length thereof, said opening having a longitudinally intermediate portion of substantially circular cross-section, said opening having an end portion disposed in said one end portion of said bearing and having a substantially circular-shaped cross-section of smaller diameter than said intermediate portion, said one bearing having another end portion mounted in said housing, said opening having a portion extending through said other end portion of said one bearing in the form of an open-sided slot having two substantially fiat, parallel oppositely disposed side walls separated from each other a distance substantially equal to the diameter of said intermediate portion of said opening, an elongated plunger recprocably mounted in said bearings for reciprocation toward and away from said one end portion of said one bearing, said plunger comprising an elongated block having one end portion of substantially circular cross-section and an intermediate portion of substantially quadrangular cross-section with two flat, substantially parallel sides, and an elongated punch of substantially circular crosssection mounted in said block and projecting therefrom, said plunger being mounted in said bearings with said one end portion of said block being journaled in said intermediate portion of said opening, said intermediate portion of said block being slidably mounted in said other end portion of said one bearing with said fiat sides of said block disposed against said fiat sides of said slot, and said punch being journaled in said portion of said opening disposed in said one end portion of said bearing, said one end portion of said bearing having a shearing edge disposed around said punch, said punch having a shoulder defining a shearing edge disposed thereon in spaced relation to the ends of said punch for reciprocation past said' first mentioned shearing edge during said'reciprocation of said plunger, and means connected to said plunger for operatively connecting the latter to such a portable tool for reciprocation thereby.

References Cited in the file of this patent UNITED sTATEs PATENTS Number 

